1. Field of the Invention
The present invention relates to the field of high voltage switching to provide sequential ignition in internal combustion engines. More specifically, the present invention relates to a single distributor which provides high voltage switching to a plurality of spark plugs in each cylinder of an internal combustion engine.
2. Description of the Prior Art
Several patents have issued which describe high voltage distributor constructions for dual ignition systems. Among those, the following are considered to be informative in describing the state of the prior art:
U.S. Pat. No. 2,756,268 describes a distributor for directing electrical impulses simultaneously to pairs of spark plugs, in a predetermined sequence. Input electrodes, from the magneto, are found in the lower case of the distributor in diametrically disposed locations. Inner and outer rings of output electrodes are arranged in the distributor cap and a rotor element, having two separate electrode bars, rotates to provide electrical connection between one input electrode and an output electrode of the inner ring and also to provide simultaneous electrical connection between a second input electrode and an output electrode of the outer ring. It is noted that each of the input electrodes are alternately connected to output electrodes of the inner and outer rings.
U.S. Pat. No. 3,894,202 describes an ignition system for a rotary internal combustion engine, which simultaneously directs ignition spark energy produced by separate ignition coils to leading and trailing spark plugs in the same combustion chamber of the engine. The distributor cap contains two fixed arcuate shaped input electrodes having approximately the same radius of curvature and being disposed about a central axis of the distributor in an oppositely disposed relationship. Output electrodes are disposed in a ring within the distributor cap concentric with the circle formed by the arcuate input electrodes. A rotor element has two diametrically disposed U-shaped electrodes imbedded therein to provide arc-gap connection between the respective input electrodes and the associated output electrodes. It is noted that each of the U-shaped rotary electrodes alternately provide arc-gap connection between the first input electrode and its associated output electrodes and the second input electrode and its associated output electrodes.
U.S. Pat. No. 4,023,546 describes a distributor for an internal combustion engine, wherein at least two high voltage pulses are respectively distributed to at least two spark plugs per cylinder of the engine. The distributor is shown as having a cap member in which all output terminals are mounted. A first high voltage input terminal is centered at the top of the cap and is in frictional contact with a first conducting element of a rotor. The first conducting element of the rotor rotates to define an inner circle. A first set of spark plug electrodes are arranged around the first inner circle for arc-gap connection by the rotating first rotor element. A second input terminal is located at the side of the distributor cap and is in friction contact on a slip ring of a second conducting element on the same rotor. A blade extends from the slip ring and traces a circle displaced from and in a larger diameter than the inner circle. A second set of output electrodes extend from the cap and are arranged so as to be in arc-gap communication with the second conducting element of the rotor.
U.S. Pat. No. 4,064,858 describes an ignition distributor which, in one embodiment, is used with a plurality of ignition coils which discharge simultaneously. The distributor cap includes a conventional center high voltage input terminal which supplies high voltage through a carbon brush to a rotating rotor conducting element. A first set of spark plug electrodes are arranged in an inner circle to be contacted by the rotor conducting element. The rotor has a second connecting element in the form of a ring which is located at the lower perimeter of the rotor. A second high voltage input terminal makes contact with the ring type rotor element through a carbon brush. The ring type rotor element has a tab extending therefrom which contacts with a second set of output electrodes which are evenly arranged around the path of rotation of the tab.
U.S. Pat. No. 3,504,141, although not associated with a dual ignition system, teaches a rotary distributor whereby the spark plug wires are attached thereto in a non-crossover arrangement and are connected to corresponding contacts within the distributor by a printed circuit board element when the cap and the housing are assembled.
U.S. Pat. No. 3,646,922, although not associated with a dual ignition system, teaches a distributor which provides for a set of spark plug contacts to be molded into the distributor cap and a second set of spark plug contacts to be molded into the housing and wherein the wires are connected through the sides of the distributor.